Children perpetuate competence-based inequality when they help peers

Exchanges of help between children are common and often have positive consequences. But not all help is equally beneficial, for example because some help does not provide an opportunity to practice and develop skills. Here I examine whether young children might perpetuate competence-based inequality by providing incompetent peers with less opportunity to practice and improve their skills compared to competent peers. Study 1 (N = 253, 6–9 years) shows that young children understand not all help is equally beneficial: Children think that peers who receive empowerment (hints) vs. non-empowerment (correct answers) help can learn more. Study 2 (N = 80) and 3 (N = 41) then assessed children’s (7–9 years) actual helping behavior in a lab-based experiment. Through a cover story, participants were introduced to two unknown, same-age children whom they later overheard were either good or not good at solving puzzles (Study 2) or math (Study 3). Subsequently, participants got to help both of them with a puzzle-quiz (Study 2) or a math-quiz (Study 3) by providing either empowerment or non-empowerment when they asked for help. Across both studies, children were more likely to provide empowerment help to competent peers, and non-empowerment help to incompetent peers. This work suggests that when young children perceive differences in competence (e.g., based on stereotypes), they contribute to maintaining the status quo by providing the most vulnerable students, that would profit the most from improving their skills, less opportunity to do so

Decomposed versus integrated control of a one-stage production system

This paper considers the case of a one-stage production system with several products and operating under tight production capacity constraints. The production schedule is cyclical, and there are long and sequence dependent setup times. The production system is regarded to consist of two components, namely a production unit and an inventory unit. The performance, with respect to inventory costs, timing and production quantity determination, of two types of control of the production system are compared, namely so-called decomposed and integrated control. For the generation of production orders, decomposed control uses only information from the inventory unit, while integrated control combines the information from both units. The main conclusion, based on simulation experiments, is that the inventory costs are just slightly lower in case of integrated control. Integration outperforms decomposition with respect to timing and quantity determination. However, since the differences between both approaches are small, the less sophisticated approach of decomposition is preferable when choices between both types of control have to be made.

Health, Medicine and the Media

Far more deeply than most of us realize, the media (in particular film, but also television, magazines, newspapers, and, more recently, the internet) has been intrinsic to the history of medicine and public health. For many of us, what we know about public health, medicine, and disease has come to us through the media. The medical profession, and public health policies, came into being in their modern forms during the second part of the nineteenth century, as medicine professionalized and as public health became defined, codified and embodied in government bureaucracies as well as public and private institutions. These developments have coincided with, and relied upon, the growth of popular media that reached audiences of a variety of classes and backgrounds. Images of physicians, as well as images of health and disease, are disseminated through the modern media. In fact while we know a great deal about the way images have functioned in the history of health and medicine, much remains to be explored with respect to the role of the media in the history of health and medicine. In addition to providing diversion and entertainment, the media provide us with messages about health and disease (as every newspaper and magazine editor knows, these stories are read by the public with great interest). Public health officials have often aimed to mimic the way the media entices the public by presenting health information in ways that are entertaining. The medical profession itself has only a limited influence on these representations. As a consequence, medical and media understandings of health and disease do not always coincide. This volume offers a smorgasbord exploration of some of the issues arising from the at times amicable and at other times rather strained relationship between medicine and the media over the past century in the only-just-postcolonial zone of Australia, New Zealand and Indonesia. It carries us from the health education movies made for Indonesians in the 1930s and Maoris in the 1950s to the sex education movies for the white Australian public catching up with the sexual revolution of the 1970s. Its authors analyse portrayals of physicians and medical knowledge in contemporary film and television, such as the depiction of a physician diagnosing homosexuality in Heavenly Creatures and a troubled female medical student in Charlene Does Med at Uni. As a result, the articles in this volume stimulate us to explore the relationship between health and medicine and the media in much greater detail

Racial Stereotype Application in 4-to-8-Year-Old White American Children: Emergence and Specificity

Young children’s racial stereotyping is poorly understood even though stereotyping can influence individuals’ attitudes and behavior toward others. Here we present two preregistered studies (Total N = 257) examining White American children’s (4–8 years) application of six stereotypes (about being American, smart, wealthy, sporty, honest, and nice) when considering Asian, Black, and White children. We observed clear and consistent evidence for one cultural stereotype across the two studies: participants indicated that Asian and Black children were less American than White children. In a measure of racial attitudes, participants also preferred White children over Black and Asian children. Taken together, this research suggests that, in contrast to findings from previous work, White American children only consistently applied stereotypes about being American. Moreover, this research suggests that children’s cultural stereotypes might diverge from children’s attitudes early in development. These studies raise new questions about the emergence of racial stereotype application early in childhood–including how best to study it

The effect of moderate alcohol consumption on adiponectin oligomers and muscle oxidative capacity: a human intervention study

Aims/hypothesis The aim of this study was to investigate whether moderate alcohol consumption increases plasma high molecular weight (HMW) adiponectin and/or muscle oxidative capacity. Materials and methods Eleven lean (BMI 18 - 25 kg/m(2)) and eight overweight ( BMI >= 27 kg/m(2)) men consumed 100 ml whisky (similar to 32 g alcohol) or water daily for 4 weeks in a randomised, controlled, crossover trial. After each treatment period, muscle biopsies and fasting blood samples were collected. Results Adiponectin concentrations increased ( p <0.001) by 12.5% after 4 weeks of moderate alcohol consumption. Moderate alcohol consumption tended to increase HMW adiponectin by 57% ( p= 0.07) and medium molecular weight adiponectin by 12.5% ( p= 0.07), but not low molecular weight (LMW) adiponectin. Skeletal muscle citrate synthase, cytochrome c oxidase and beta-3-hydroxyacyl coenzyme A dehydrogenase (beta-HAD) activity were not changed after moderate alcohol consumption, but an interaction between alcohol consumption and BMI was observed for cytochrome c oxidase ( p= 0.072) and citrate synthase ( p= 0.102) activity. Among lean men, moderate alcohol consumption tended to increase cytochrome c oxidase ( p= 0.08) and citrate synthase activity ( p= 0.12) by 23 and 26%, respectively, but not among overweight men. In particular, plasma HMW adiponectin correlated positively with activities of skeletal muscle citrate synthase ( r= 0.64, p= 0.009), cytochrome c oxidase ( p= 0.59, p= 0.009) and beta-HAD ( r= 0.46, p= 0.056), while such correlation was not present for LMW adiponectin. Whole-body insulin sensitivity and intramyocellular triacylglycerol content were not affected by moderate alcohol consumption. Conclusions/interpretation Moderate alcohol consumption increases adiponectin concentrations, and in particular HMW adiponectin. Concentrations of HMW adiponectin in particular were positively associated with skeletal muscle oxidative capacity

Moderate alcohol consumption increases insulin sensitivity and ADIPOQ expression in postmenopausal women: a randomised, crossover trial

Aims/hypothesis To determine whether 6 weeks of daily, moderate alcohol consumption increases expression of the gene encoding adiponectin (ADIPOQ) and plasma levels of the protein, and improves insulin sensitivity in postmenopausal women. Methods In a randomised, open-label, crossover trial conducted in the Netherlands, 36 apparently healthy postmenopausal women who were habitual alcohol consumers, received 250 ml white wine (~25 g alcohol/day) or 250 ml of white grape juice (control) daily during dinner for 6 weeks. Randomisation to treatment allocation occurred according to BMI. Insulin sensitivity and ADIPOQ mRNA and plasma adiponectin levels were measured at the end of both periods. Insulin sensitivity was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Levels of ADIPOQ mRNA in subcutaneous adipose tissue were determined by RT-PCR. Results All subjects completed the study. Six weeks of white wine consumption reduced fasting insulin (mean¿±¿SEM 40.0¿±¿3.4 vs 46.5¿±¿3.4 pmol/l; p

cAMP-Dependent Co-stabilization of Axonal Arbors from Adjacent Developing Neurons

Axonal arbors in many neuronal networks are exuberant early during development and become refined by activity-dependent competitive mechanisms. Theoretical work proposed non-competitive interactions between co-active axons to co-stabilize their connections, but the demonstration of such interactions is lacking. Here, we provide experimental evidence that reducing cyclic AMP (cAMP) signaling in a subset of retinal ganglion cells favors the elimination of thalamic projections from neighboring neurons, pointing to a cAMP-dependent interaction that promotes axon stabilization

Gene-Environment Interaction Research and Transgenic Mouse Models of Alzheimer's Disease

The etiology of the sporadic form of Alzheimer's disease (AD) remains largely unknown. Recent evidence has suggested that gene-environment interactions (GxE) may play a crucial role in its development and progression. Whereas various susceptibility loci have been identified, like the apolipoprotein E4 allele, these cannot fully explain the increasing prevalence of AD observed with aging. In addition to such genetic risk factors, various environmental factors have been proposed to alter the risk of developing AD as well as to affect the rate of cognitive decline in AD patients. Nevertheless, aside from the independent effects of genetic and environmental risk factors, their synergistic participation in increasing the risk of developing AD has been sparsely investigated, even though evidence points towards such a direction. Advances in the genetic manipulation of mice, modeling various aspects of the AD pathology, have provided an excellent tool to dissect the effects of genes, environment, and their interactions. In this paper we present several environmental factors implicated in the etiology of AD that have been tested in transgenic animal models of the disease. The focus lies on the concept of GxE and its importance in a multifactorial disease like AD. Additionally, possible mediating mechanisms and future challenges are discussed

Moderate alcohol consumption lowers the risk of type 2 diabetes: a meta-analysis of prospective observational studies

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Alcohol consumption, physical activity, and chronic disease risk factors: a population-based cross-sectional survey

BACKGROUND: Whether the association of alcohol consumption and cardiovascular disease is the product of confounding and the degree to which this concern applies to other behaviors are unclear. METHODS: Using the 2003 Behavioral Risk Factor Surveillance System, a population-based telephone survey of adults in the US, we compared chronic disease risk factors between 123,359 abstainers and 126,674 moderate drinkers, defined as intake of ≤ 2 drinks per day among men and ≤ 1 drink per day among women, using age- and sex- and multivariable-adjusted models. We also compared sedentary and active individuals, defined as moderate physical activity ≥ 30 minutes per day for ≥ 5 days per week, or vigorous activity for ≥ 20 minutes per day on ≥ 3 days. RESULTS: Chronic disease risk factors and features of unhealthy lifestyle were generally more prevalent among abstainers than drinkers in age- and sex-adjusted analyses, but these differences were generally attenuated or eliminated by additional adjustment for race and education. For low fruit and vegetable intake, divorced marital status, and absence of a personal physician, adjustment for race and education reversed initially positive age- and sex-adjusted associations with abstention. Comparison of sedentary and active individuals produced similar findings, with generally lower levels of risk factors among more physical active individuals. CONCLUSION: The differences between abstainers and drinkers are attenuated after adjustment for limited sociodemographic features, and sedentary and active individuals share a similar pattern. Although observational studies of both factors may be susceptible to uncontrolled confounding, our results provide no evidence that moderate drinking is unique in this regard. Ultimately, randomized trials of all such lifestyle factors will be needed to answer these questions definitively